The Bill and Melinda Gates Foundation has awarded a
$100,000 grant to a couple of researchers investigating the use of ultrasound
as a reversible male contraceptive.

The technique already works on rats, according to James
Tsuruta, of the University
of North Carolina, who
led the research.

"We think this could provide men with
reliable, low-cost, non-hormonal contraception from a single round of
treatment," he said.

The focus now is to come up with a therapeutic
ultrasound that would safely deplete testicular sperm counts, which presumably
would presage the development of a cheap (and reversible) method of
contraception for men.

A hat tip to Discovery Magazine for noticing this
item. While details about how the device would function still remain scarce,
since sperm don't like excessive heat, Discovery suggests the process
may involve "heating and shaking working in combination."